The SIG ASP20 is powerful, accurate and consistent gas ram air rifle. Accuracy is excellent with the right pellets. It has a quality finish and sophisticated design. The price is right and the brand name is tops for a huge number of shooters.

It's a clear HAM Gold Award winner!

The ASP20 is SIG Air's first completely in-house designed and manufactured airgun. Expectations are high: the ASP20 delivers. It will certainly be a huge success.

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Full Review

VALUE FOR MONEY

As a break barrel air rifle, the SIG ASP20 is priced towards the upper end of the price range. It’s competing in the same price bracket as a number of Diana, Walther and Weihrauch products – both spring/piston and gas ram-powered.

The Street Price is $429.99 for the wood stocked version tested here and $349.99 for the synthetic model – at the time of writing, at least.

Of course, a SIG-designed and manufactured air rifle was never going to be a bargain basement product. SIG is just not that sort of company. A concentration on quality and performance is foremost in the minds of every SIG employee that I have met. That’s what we see in the SIG ASP20.

In fact such is the perception of the SIG brand that a number of people have told me they think the gun is less expensive than they expected. That’s the power of the company’s brand and it must be good news for SIG!

HAM Tester Eric Brewer is an experienced spring/piston shooter who competes successfully in Field Target competition. He couldn’t wait to test the ASP20. In his test notes, Eric wrote: “At $430 the ASP20 is rather high priced for a breakbarrel – until you shoot it! I will own one!”

The ASP20 scope bundle tested by HAM is not yet available at retail. However, SIG tells us that they expect the price for the bundle of ASP20 and Whiskey3 ASP scope with rings to be about $150 above that of the “bare gun” price. That would be between $500 and $600, depending on the stock – a very attractive price for a bundle of this quality.

All of this, together with the performance of the ASP20 on test, means the ASP20 is clearly excellent value for money.

SPEED AND ACCURACY

The SIG ASP20 tested by HAM achieved a peak Muzzle Velocity of 1294.2 FPS when using H&N Field Target Trophy Green pellets. These light, 5.56 Grain alloy pellets also gave outstanding accuracy in HAM testing.

Unsurprisingly, the fastest lead pellets in the standard HAM test suite were the light 7.0 Grain RWS Hobbys. These gave an average FPS of 1150 FPS.

It’s interesting to note that the SIG ASP20 tested by HAM performed well with most pellets. However it really did not like the 4.7 Grain Gamo Platinums. Muzzle Energy was well down and Standard Deviation very high when compared to the other HAM test pellets. The test target shows that accuracy suffered accordingly.

Pellet

Average Muzzle Velocity

Average Muzzle Energy

Accuracy

Gamo Raptor Platinum 4.7 Grain

1276.20 FPS

17.00 Ft/Lbs

OK

H&N Field Target Trophy Green 5.56 Grain

1294.20 FPS

20.68 Ft/Lbs

Excellent.

RWS Hobby 7.0 Grain

1149.83 FPS

20.56 Ft/Lbs

Very Good.

Crosman Premier HP 7.9 Grain

1073.26 FPS

20.21 Ft/Lbs

Very Good.

JSB Exact Diabolo 8.44 Grain

1052.58 FPS

20.77 Ft/Lbs

Excellent. Best Tested.

H&N Field Target Trophy 8.64 Grain

1035.13 FPS

20.59 Ft/Lbs

Very Good.

H&N Baracuda Match 10.65 Grain

926.47 FPS

20.30 Ft/Lbs

Very Good.

At 25 Yards, HAM Tester Eric Brewer put 8 out of 10 JSB Exact pellets into a 0.5 x .025-inch group, making him very happy! As you can see, he manfully takes responsibility for the two fliers. Let’s blame the 23 degree F temperature for that and thank Eric for his dedication to HAM testing in such weather!

TRIGGER AND COCKING EFFORT

The average trigger pull weight of the SIG ASP20 tested by HAM was 2 Lbs 1 Oz.

This is, of course, a light pull for such a powerful gas ram air rifle. SIG Air makes much play of the fact that the ASP20’s trigger can be predictably and safely adjusted. This is true. However, as always, we shot the test gun with the trigger “as received”.

HAM Tester Eric Brewer found the trigger feel to be rather long and spongy. At first, the sear break seemed hard to find. But he did find that he could predict the release point after a little practice. Now he’s really keen to start adjusting the trigger to his own preferences!

This trigger can be adjusted for a single- or two-stage pull. Or, indeed, a point in between! We covered the theory of this in a previous HAM story. So Eric has some more fun ahead of him there…

The ambidextrous safety is manual, which many serious shooters appreciate. It’s positioned exactly where your trigger finger should be when it’s not on the trigger! This sliding safety works well, demanding definite effort to engage and disengage.

COMPARISON TO MAKERS CLAIMS

The power claim for the SIG ASP20 is in the product name. The “20” in ASP20 indicates this air rifle’s Muzzle Energy in Ft/Lbs. That would be 20 Ft/Lbs…

The ASP20 tested by HAM exceeded this power claim with every pellet except the ultra-light Gamo alloys.

Wisely, SIG Air is stressing Muzzle Energy as an indication of power for the ASP20, rather than Muzzle Velocity. This is a smart move and one that is shared by too few other airgun manufacturers. It removes the ambiguity of FPS claims given that raw speed is so dependent on many factors. As you can see from this test review, the “fastest” pellets produced the lowest “power”. That’s not an unusual situation!

Now SIG does specify – with great precision – that the ASP20 in .177 caliber has a Muzzle Velocity of “up to 1021 FPS using 8.64 Grain pellets”. The SIG ASP20 tested by HAM also met and beat that claim. We saw 1035 FPS when shooting 8.64 Grain H&N Field Target Trophy pellets.

The manufacturer specifies an adjustable trigger pull weight of between 2.5 and 4.0 Lbs. The SIG ASP20 tested by HAM recorded a trigger pull weight averaging 2.0 Lbs. We’re OK with that…

Another claim by SIG is that the cocking effort is lower than other breakbarrel air rifles of this power level. HAM agrees with that too. We found the cocking effort to be 32 Lbs.

That’s significantly lower than we would expect for a 20 Ft/Lb breakbarrel. It’s even a little lower than SIG’s estimates.

CONSISTENCY

The SIG ASP20 tested by HAM delivered great consistency. At least with everything except the Gamo Platinum pellets!

Excepting the Gamos, Muzzle Energy varied only between 20.21 and 20.77 Ft/Lbs. This is a very tight range for a gas ram air rifle.

And Standard Deviation – the measure of shot-to-shot consistency in a string – was also very low at an average of just 4.44 FPS. Adding-in the enormous and atypical Standard Deviation of 42.22 FPS for the Platinum pellets, the average climbed to 9.8 FPS.

Trigger pull weight varied by just plus or minus 2 Ounces around the 2 Lbs 1 Ounce average. Again, this is very good consistency.

NOISE LEVEL

The SIG ASP20 is fitted with a built-in silencer. This worked well, taming the report to backyard-friendly levels. The HAM Team assessed the noise level as being about average for a silenced breakbarrel air rifle.

However, note that it’s possible for the ASP20 to shoot light .177 caliber pellets at FPS levels higher than the Speed Of Sound (around 1100 FPS). In this case, there will be a significant crack as the pellet travels through the air.

No built-in silencer or suppressor can deal with such a sonic boom! In that case, the answer is simply to use heavier pellets weighing 8 Grains or more. That will lower the Muzzle Velocity sufficiently to restore backyard-friendly sound levels.

SIGHTS AND SCOPE

The SIG ASP20 is supplied either without a scope or – in future – bundled with a SIG Whiskey3 ASP 4 – 12 x 44AO scope. This SIG scope was included with the HAM test gun.

This Whiskey3 ASP scope has been designed to operate with a pellet drop compensation elevation turret. This works exactly like the BDC scope turrets which are increasingly popular in firearms use.

The scope is calibrated by first zeroing at a set range – say 30 yards. The turret is then set to that zero range. Elevation changes are then made based on the distance to any specific target. These graduations can be seen in the photograph below. (Note how there is a larger rotational angle between the 70 and 60-yard markers and the 50 – 60 yard ones).

Of course, to work correctly, the pellet drop compensation turret needs to be graduated to the specific combination of airgun and pellet being used. The first SIG AIR ASP20 air rifles shipping in .22 caliber with a bundled scope have the SBT compensation turret installed.

However, .177 guns – like the HAM test example – have a regular elevation turret. SBT turrets for .177 cal will be available in future.

The potential for scope creep is eliminated on the SIG ASP20, thanks to the Picatinny rail laser welded to the compression tube. Neither scope, nor rail is going anywhere! (Laser welding is used in the ASP20 to prevent the distortion that can occur to parts when using other welding techniques. SIG Air tells us).

SHOOTABILITY

The SIG ASP20 does not have an adjustable cheek piece or butt plate. But in spite of that, it still fits most people well. The wrist of the stock is well-dimensioned. It allowed the trigger finger to engage the blade naturally, with no strain.

HAM testers found handling and pointability to be good. The center of gravity of the gun is also exactly where we put our forehand when shooting the gun. Again this makes for comfortable, consistent shooting in the field.

This means that the ASP20 is a new addition to that select group of air rifles – including the Air Arms TX200 and Weihrauch HW100 – that feel “just right” as they come from the factory, with no need for the stock adjustments they don’t have.

In his test notes, HAM Tester Eric Brewer wrote: “It can shoot! Very nice. You have to pay attention and be consistent but there’s less kick than I expected”.

HAM testers found the Artillery Hold – pivoting the forend on your open palm – to give the best consistent accuracy. Like most powerful gas ram and spring/piston air rifles, holding the gun tightly (like a firearm) will ruin the accuracy. There’s some jump when fired, of course, but it’s less than we were expecting.

As previously mentioned, cocking effort was low for the power level. This makes the ASP20 suitable for plinking as well as hunting. There’s a good chance that some will find their way to Field Target matches also.

The weight of the ASP20 and Whiskey3 scope tested by HAM was 9 Lb 11 Oz. This is heavy enough to feel substantial, yet not so heavy as to be unmanageable for many shooters. The overall length of 45.5 Inches is in line with expectations for a breakbarrel air rifle of this power.

APPEARANCE AND FINISH

With the company’s focus on military weapons, it’s no surprise that the SIG ASP20 has a tactical look to it. The appearance takes design keynotes from the SIG SSG3000 centerfire rifle, particularly in the design of the trigger and stock. This is not your traditional wood-stocked springer look!

So, while appearance will be a matter of personal taste, the HAM team likes it. We feel it looks sleek and sophisticated. Well, except for that “straight” trigger blade, perhaps.

The dark stain of the hardwood – actually beech – stock makes it surprisingly difficult to tell it apart from a synthetic stock. However, once you look closer, you can see that it’s beautifully machined and finished. The quality of the stippling and the company logo are excellent, as you can see from these close-up photographs.

All metal parts exhibit high quality machining. Surface finish of the metal parts is a military-style matt black.

This is SIG’s tough Nitron Coating. It’s the same as used on the company’s firearms. Metal parts are dipped and then baked to make a tough, long-lasting finish.

As expected from a SIG. There’s definitely no danger of unwanted reflections spooking your prey when hunting with an ASP20!

You’ll see that serial numbers for the SIG ASP20 all begin with the initials JDH. This unusual prefix is a memorial to Justin Daniel Heckert, one of the gun’s key design engineers.

Sadly, Justin died unexpectedly before the ASP20 entered production. Serial number one of the SIG Air ASP20 was presented to Justin’s family as a mark of respect by the company.

BUYING AND OWNING

SIGAIR has spent time, effort and money on the packaging. That’s really important to ensure that your new air rifle arrives in perfect condition – in spite of whatever the parcel delivery company may do to it en route!

As we see below, the SIG ASP20 is carefully packaged in a high quality foam cutout. There’s more foam under the top lid, too.

This quality of packaging is very impressive and it’s part of a clear trend among some airgun manufacturers to provide improved packaging for their products. It’s waaay better than the minimal packaging protection provided by many other manufacturers.

The owner’s manual is comprehensive and well illustrated. It’s in multiple languages, including English, German, French, Italian and Spanish.

Given SIG’s huge customer base of powder burner shooters, there’s a section of “Special Notes To Firearms Shooters”. This gives basic advice for holding the ASP20 for best accuracy, together with a stern warning not to use a riflescope intended for centerfire use only! This is sensible, correct advice, so long as owners bother to read the instructions. RTFM springs to mind!

Also included with the SIGAIR ASP20 is a hangtag with essential safety information and a screwdriver and Allen wrench for trigger adjustment. Because this gun was bundled with the SIG Whiskey3 ASP 4-12×44 scope, there’s also a Torx wrench for the scope ring screws.

The ASP20 is supported by a 5-year warranty. Almost yesterday, it seems, most airguns had a 12-month warranty. Increasingly multi-year warranties are becoming more common on mass market air rifles and this SIG warranty is among the longest. That’s obviously great for the consumer.

10 YARD TEST TARGETS

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